Sand settling plant



July 30, 1935. F. MIEDER SAND SETTL ING PLANT Filed Aug. 20, 1932Patented July 30, 1935 UNITED STATES PA NT QFFlCE Application August 20,1932, Serial No. 629,679 In Germany August 28, 1931 Claims.

5 and outlet channels, a collecting reservoir or sink-hole disposed onthe bottom of the basin at the end thereof, and a water-retaining wallinserted in the basin and corresponding in widthand shape to the crosssection thereof except for a narrow slit at the bottom of the basin. The

' water dammed up by the retaining wall rushes through this slit at highspeed and in so doing entrains the sand that has settled on the floor ofthebasin from the water flowing through the latter and carries it awaytowards the end of the basin, the sand being simultaneously rinsedthoroughly and thus freed from particles of organic matter that might becontained therein. The retaining-wall can be rearranged from time totime or gradually carried along by the water flowing through the basin,though it is'preferably slowly moved in a direction opposite to thedirection of flow of the waste water to increase the latters velocitywhen passing through the slit. When the retaining-wall is to be movedthis way, it has been found to be particularly advantageous to arrangeit obliquely to the bottom of the basin and with. the top edge leadingin the direction of motion of the wall. erably mounted on a carriagecapable. of moving on the side walls of the settling basin and can becompletely removed therefrom for transfer to an adjacent basin by meansof a traveling platform.

By way of example, one form 'of the settling basin and of the devicerequired for rinsing and removing the sand during operation isillustrated in the accompanying drawing, in which Figure 1 is alongitudinal section of the settling basin provided with aretaining-wall and carriage for same;

Fig. 2 is a top view of Fig.1;

Fig. 3 is a cross section on the line A-B, of Fig. 1; and

Fig. 4' is a Fig. 1.

Referring to the drawing, I is the covered supplychannel for the wastewater, which is divided into the two open grooves 2 each of which crosssection on the line CD, of

- opens into a sand settling basin 3 whose bottom 4 extends into adepression or sink-hole 5 and pref- The retaining-wall is pref-- s (Cl.209208) This invention relates to a sand settling plant channels inwidth and depth so as to appreciably reduce the velocity of the waterflowing through them and thus cause the sand to be separated from thewater and settle on the bottom. A distributor 30 having the shape of ablind is pro- 5 vided at the inlet of each basin 3 to insure uniformflow of the water therein.

A retaining-wall linserted in one of the basins 3 takes up the entirecross section thereof with the exception ofa slit between its lower edgeand the bottom of the basin. As Fig. 4 shows, the

lower edge 2| of the wall I may have the form of a .rake the teeth ofwhich rest on the bottom of the basin and permanently determine theheight of the slit. The water passing through thebasin 3 necessarily hasto flow through the small slit between the lower edge of the wall I andthe bottom 4, so that its velocity and force will be much greater atthis point than elsewhere in the basin 3, and it is due to thisincreased velocity and force that the sand deposited on the bottom 4will be whirled up and carried away to the end of the basin 3.In'order'to remove the sand from all parts of the bottom {theretaining-wall l is displaced from time to time or it may be mademovable and permitted to drift slowly from the inlet to the outlet ofthe basin 3 with the flow of the water. A still better arrangement;however, is to provide for positive motion'of the wall 1 in a Idirection opposite to that of the flow of the water and thereby increase'the velocity and force of the water flowing through the slit to'a veryconsiderable degree. In this case, the wall I is preferably inserted inthe basin 3 so-that its lower edge leads relative to itsupper edge inthe direction of flow of the water.

The retaining-wall 1 is moved from one end of the basin 3 to the otherby a carriage 8 which I travels on the rails 9 disposed on the sidewalls of the basin 3. The wall' I is secured to the carriers I0 movablyconnected with their ends to the carriage 8. One side of the wall 1 isengaged by the wire ropes II the free ends of which are fastened ontothe drum I! of a winch l3 disposed in the carriage 8. The ropes ll.serve for adjusting the size of the slit or gap according to the heightof the accumulated sand and also for lifting the wall I out of the basin3, sothat the carriage 8 of the 'wall I may be moved to an adjacentbasin by means of the travelling platform ll. To prevent the wall Idisposed oscillatorily so to speak on the carriage 8 from being liftedout by the fiow of the water, additional wire ropes l5 engage the otherside of the wall I and can be wound up on a drum It in the carriage 8,the 55 drums I: and It being preferably brought into engagement byimeansof the cogwheels II to cause the wire ropes of one drum to be wound up Iwhile those of the other drum are being unwound. 'lhe winch may beoperated by hand or motor and the carriage 8 may be moved over therailsI either manually or by means of the motor I.

Ifthebottoml ofthesettlingbasinllsarranged horizontallyl the wall I canmoved over the entire length of the basin 3 wi out requiring a change inadjustment, but if a sloping bottom is used, it will be necessary toadjust the wall 1- during its motion from one end of the basin 8 to theotheraccording to the angle of inclination of the bottom .to preventvariation in the size of the gap between the lower edge of the wall Iand the bottom [of the basin 3.

Owing to the great velocity and force of the water flowing through thegap, the sand is not only moved forward but thoroughly rinsed also, sothat organic particles contained therein are separated and dischargedthrough the outlet. To remove the last remnants of organic admixturesfrom the sand collecting in the depression or sink-hole I of the basin 8and thus perfectly purify it, the bottom of the hole is preferablyprovided with meansfor inJecting finely distributed water under pressureor compressed air into the sand accumulation, such as the ventilatorbo;5a supplied with compressed air by the pipe connection 5b. To preventthe stirred up sand from entering the outlet channel 0 a sealing walliaaddustable as to height is ar-, ranged in front of the channel I andadjusted to such a height during rinsing that the whirl of sand cannotpass over it. This confining wall to is pre ferably disposed so astopermit of quick raising and lowering for thepurpose of rapidly ceasingthe damming of the waterafter rinsing to insure the removal ofthe washedout organic matter by the rush of the current as long as it is still insuspension. In mg. 2 two settling plants are arranged side by side andboth are in communication by branch channels with the supply and outletchannels, the rotary door 22- serving for rendering one or the otherplant inoperative.

The sand'can also be advantageously removed from the hole or depressioni by means of the grippers 23 or in othersuitable manner.

Iclaim:-- 1. Sand settling plant in clarifying works, comprising abasin,a supply channel at one end of the basin and an outlet channel on theother end of the basin, the width of the basin being larger than thewidth of the two channels and the bottom of the basin being lower thanthe bottom of the two channels, a sink-hole onthe bottom of thebesln'near the outlet channel, a water-rewall arranged in and extendingacross the basin and corresponding in width and shape with the crosssection of the basin, the said wall leaving a small gap between itslower edge and .the bottom of the basin and being movable along -thebasin, and means for moving the wall against the flow of the water.

prising a basin, a supply-channel at one' end of the basin and an outletchannel on the other end of the basin, the width of the basin beinglarger than the width of the two channelsand the bottom ofthebasinbeinglowerthanthebottom of the two channels, a sink-hole on thebottom of 2. Sand settling plant in clarifying works, com

thebasin and an outlet channel on the other end of the basin, the widthof the basin'being larger.

than the width of the two channels and the bottom of the basin beinglower than the bottom 01' the two channels, a sink-hole on the bottom ofthe basin near the outlet channel, a removable water-retaining wall ofgreater height than the highest water level in said basirharranged inand extending across the basin and corresponding in width and shape withthe cross section of the basin but leaving a small gap between its loweredgeand the bottom of the basin, whereby the liquid carrying the sandcan pass through the gap, whilst no liquid can passoverthe topoftheretaining wall, and rapidly movable sealing means arranged in frontof said outlet channel. 4. Sand settling plant in clarifying works, comprising a basin, a supply channel at one end of the basin and an outletchannel on the other endof the basin, the width of the basin beinglarger than the width of the two channels and the bottomof thebasinbeing lower than the bottom of the two channels, a sink-hole on theof the basin near the outlet channel, a removable water-r'etainingwall'of greater height than the highest water level in-said arranged inand extending across the basinand correspond- I ing in width and 'shapewith the cross section ofthe basin but leaving a small gap between itslower edge and the bottom of the basin, wherebf the gap, whilst noliquid can pass over/the top,

the liquid carrying the sand can pass: through of the retaining wall,and ventilating means provided on the bottom of the sink-hole.

5. A- process of cleaning sand settling. chambers and the like whichconsists in obstructing the flow of liquid therethrough and raising thelevel of the liquid on the'iipstream side of the obstruction whilepermitting flow ofliquid at the point of obstruction immediatelyadjacent the bottom of the chamber torcause a local high velocity offlow at the point of obstruction and moving the obstruction in anupstream direction.

